Hydrogensulphates of silver(I) and some transition-metal cations

Abstract

Pure Ag[HSO₄] cannot be made by fusing mixtures of Ag₂[SO₄] and H₂SO₄in accord with a derived phase diagram, but can be precipitated from Ag[O₂CCF₃] and H₂SO₄ in CF₃CO₂H. Tetra- and hepta-solvates result from contacting Ag₂[SO₄] and H₂SO₄ in acetonitrile; the rate of solution of the sulphate controls the overall reaction. Hydrogensulphates of di- and tetra-solvated transition-metal ions (Cu^I, Cu^II, Zn^II, Cd^II, Mn^II, Fe^II, and Ni^II) can be made by metathesis of their halides and Ag[HSO₄] in MeCN, or by attacking the metals with dilute solutions of H₂SO₄ in MeCN. The inability to desolvate these salts without loss of H₂SO₄ is correlated with the strength of the Mⁿ⁺–NCMe interaction. The solubilities of Ag[HSO₄] in organic solvents are explained in terms of depolymerization of hydrogen-bonded anions.